Hopefully functional Xbatalarm for nonfunctional ACPI. Copy to /usr/bin/xbatalarm and reboot. Original file by QuaLaPinna.

xbatalarm

#!/bin/bash
# Copyright (C) QuaLaPinna team (Gius & Whitesnow, repository: http://qualapinna.dyndns.org/repo, blog: http://qualapinna.dyndns.org)
# April 2014, license: GPL3 and any later versions
# Credits: Puppy Linux forum user josejp2424 for input and collaboration in NLS development (see es_AR localized file).
# Xbatalarm version 2.0

export TEXTDOMAIN=xbatalarm
export OUTPUT_CHARSET=UTF-8

f_get_values() {
	if [ -f /proc/acpi/battery/*/state ]; then
		REAL_CHRG=$(grep remaining /proc/acpi/battery/*/state | awk '{print $3}')
		LAST_F_CHRG=$(grep full /proc/acpi/battery/*/info | awk '{print $4}')
		ALRM_MARK=$(echo "$LAST_F_CHRG * $ALRM_PERC / 100" | bc)
		CHARG_STATUS=$(grep charging /proc/acpi/battery/*/state | awk '{print $3}')
	elif [ -f /sys/class/power_supply/BAT*/uevent ]; then 
		if [ -f /sys/class/power_supply/BAT*/charge_now ]; then 
			REAL_CHRG=$(cat /sys/class/power_supply/BAT*/charge_now)
			LAST_F_CHRG=$(cat /sys/class/power_supply/BAT*/charge_full)
		else 
			REAL_CHRG=$(cat /sys/class/power_supply/BAT*/energy_now)
			LAST_F_CHRG=$(cat /sys/class/power_supply/BAT*/energy_full)
		fi
		ALRM_MARK=$(echo "$LAST_F_CHRG * $ALRM_PERC / 100" | bc)
		CHARG_STATUS=$(cat /sys/class/power_supply/BAT*/status)
	fi
}

if [ -r /etc/xbatalarm/xbatalarm.conf ]; then
	. /etc/xbatalarm/xbatalarm.conf
else
	/usr/bin/xbatalarm-config
fi

while [ true ]
do

f_get_values

	if [[ "$CHARG_STATUS" != "discharging" && "$CHARG_STATUS" != "Discharging" ]]; then 
		sleep $SLEEP_TIME
		continue
	fi

	if (( $(bc <<< "$REAL_CHRG < $ALRM_MARK") )); then
		 Xdialog --title "Xbatalarm" --center --timeout 8 --msgbox "`gettext '## WARNING! ## \n \n YOUR BATTERY NEEDS TO BE CHARGED.\n PLEASE, CONNECT YOUR CHARGER.'`" 0 0 &
			mplayer /usr/share/audio/error.wav &> /dev/null &
	fi

	sleep $SLEEP_TIME
done

exit 0